The method of producing benzaldehyde

 

(57) Abstract:

The invention relates to a method for producing a benzaldehyde - source product for production of a wide range of medicinal and aromatic substances, dyes, crop protection products. The method involves a two-step hydrolysis of benzylbromide or chlorinated aromatic compounds, with a mass fraction of benzylbromide within 75-95%. In the first stage, carry out the hydrolysis with an aqueous solution of hydrochloric acid. When acid hydrolysis is carried out at a temperature of 100-120oWith atmospheric or pressure up to 0.7 MPa, typically using a hydrochloric acid solutions with a mass fraction of hydrogen chloride within the range of 15-26% and the mass ratio of the original benzylbromide and hydrochloric acid in the range of 1:0,9-2,0. In the second stage, carry out the hydrolysis obtained in the first stage, raw benzaldehyde aqueous solution of sodium carbonate, with a mass fraction of Na2CO3within 5-20% or aqueous sodium hydroxide solution with a mass fraction of NaOH in the range 5-18%. This alkaline hydrolysis is carried out at a temperature of 100-110oWith atmospheric or pressure up to 0.7 MPa, typically in the presence of a phase transfer catalyst, usatc technology for aromatic aldehydes, namely, the method for producing a benzaldehyde - source product and a component for the production of a wide range of medicinal and aromatic substances, dyes, plant protection.

A known method of producing benzaldehyde by hydrolysis of benzylbromide water at 105-120oWith the presence of the catalyst of zinc chloride, taken in an amount of about 1% by weight of the original benzylbromide [U.S. Patent 3087967, CL 260-599, 1963]. The main disadvantage of this method is the necessity of using benzylbromide with a high content of the basic substance.

This disadvantage has the following method of producing benzaldehyde, based on the aqueous hydrolysis of pure benzylbromide at a temperature of about 100oIn the presence of 0.01 to 5% (preferably 0.1 to 1%) amines, amides, imides, pyridine and sulphonamide as catalysts [Japan Patent 12132, CL 16 51, 1969].

A known method of producing benzaldehyde catalytic hydrolysis of benzylbromide water at elevated temperatures (120-140o(C) in the presence of 0.005-1% of the dichloride or tin tetrachloride (SnCl2or SnCl4) [Patent Poland 93511, class C 07 C 47/55, 1977]. This method allows you to use technical benzanthrone mass Domas. % benzaldehyde) determines the need for additional purification of the product from impurities, which reduces the technical significance of this method.

The above drawback is deprived of the method of producing benzaldehyde hydrolysis of benzylbromide carried out in two stages: the first stage hydrolysis in aqueous medium at 120-130oIn the presence of ferric chloride as catalyst in the second stage hydrolysis in an alkaline environment (preferably in a 3% solution of sodium carbonate) at boiling [Patent Poland 54992, CL 12 8 (07), 1968] . The disadvantage of this method is the relatively low yield of the target product when used as feedstock crude (practitioning) benzylbromide.

The closest in technical essence is a method of producing benzaldehyde by hydrolysis of benzylbromide carried out in two stages: the first stage hydrolysis of benzylbromide carried out by the action of an aqueous solution of hydrochloric acid (acid hydrolysis) at a temperature of 90-100oWith a combined chlorine content is not more than 1.0%; in the second stage, the raw benzaldehyde, obtained in the first stage, when subjected to 50-100oWith alkaline hydrolysis by interaction with water is ing phases benzaldehyde allocate rectification [Patent Czechoslovakia 146828, CL 07 With 47/54, 1973]. As a source of raw materials by this method use benzanthrone obtained by distillation of the crude chlorinated mixture for the production of benzyl chloride and containing 96-99 wt.% the basic substance, not more than 1 wt. % benzyl chloride, not more than 3 wt.% benzotrichloride and not more than 0.5 wt.% ortho - and para-chloro-benzylchloride. The disadvantages of this method include the relatively low yield of the target product (85,3%), not enough high content of the basic substance (of 98.3 wt.%) and use as feedstock rectified benzylbromide, the receipt of which is connected with additional material and energy costs.

Objectives of the invention are increasing output and improving the quality of benzaldehyde (in terms of the content of the basic substance), the expansion of raw materials for its synthesis by use of cheaper gidroliznaya agents, and more affordable feedstock containing benzanthrone.

The task can be solved by hydrolysis of the crude benzylbromide or mixtures characeristics compounds (bottoms production benzyl chloride), soderjashie aqueous solutions of hydrochloric acid at 100-120oAnd atmospheric or pressure up to 0.7 MPa in the second stage by the alkaline hydrolysis of aqueous solutions of sodium carbonate (mass fraction of Na2C03within 5-20%) or sodium hydroxide (mass fraction of NaOH in the range 5-18%) at 100-110oAnd atmospheric or pressure up to 0.7 MPa in the absence or in the presence of phase transfer catalysts, taken in an amount of 0.02 to 0.5% by weight of the original crude benzylbromide.

Optimal concentrations of hydrogen chloride (Hcl) in hydrochloric acid in the first stage are concentrations within 15-26 wt.%. The increase or decrease of the mass fraction of Hcl increases the duration of hydrolysis or formation of excessive amounts of hydrochloric acid, which is technically impractical.

The optimal mass ratio of the original benzylbromide and hydrochloric acid by acid hydrolysis are the ratios of 1:0,9-2,0. Other ratios increases the duration of hydrolysis or decreases the performance of the process equipment (by increasing the amount of hydrochloric acid).

Above the concentration of the alkaline agents are best because of their red eye reduction what's agents leads to an increase in the duration of hydrolysis and decrease the selectivity of the process.

The above number (0,02-0,5%) used in the second stage catalysts phase transfer (CT MFP) are optimal, since their reduction does not reduce the duration of alkaline hydrolysis, and their increase is technically and economically feasible. As catalysts it is proposed to use Quaternary ammonium salts, for example, triethylmethylammonium chloride, tributylammonium chloride, trimethylphenylammonium chloride, tetrabutylammonium bromide or mixtures thereof, a surfactant nonionic type, for example, ethoxylated mono - and dialkylphenols (excipients OP-7 and OP-10) or polyethylene glycol (PEG-300, PEG-400, PEG-1000), or mixtures thereof.

The proposed method is illustrated by the following examples.

Example 1 (standard method).

In a three-neck reactor with a working volume of up to 900 cm3fitted with mechanical stirrer , thermometer and reflux condenser with gas outlet tube, placed 300 g of bottoms in the production of benzyl chloride with a mass fraction of benzylbromide (BH) 75,0%, benzyl chloride (HB) is 19.5%, benzotrichloride (BTH) - 3,0%, other impurities 2.5% and 270 g of hydrochloric acid with a mass fraction model HC1 - 157 MPa within 6-10 hours. Formed in the reaction of gaseous hydrogen chloride are sent to the absorbance to obtain hydrochloric acid. Upon completion of the acid hydrolysis, the mixture is cooled and in a separating funnel separating the upper organic phase containing the benzaldehyde (BAA). After separation of the receive 221,5 g crude benzaldehyde, which is directly used at the stage of alkaline hydrolysis.

At the same time get 255 g of hydrochloric acid with a mass fraction of hydrogen chloride is 20.5%, which is directly used at the stage of acid hydrolysis in the next operation of synthesis or pre-diluted with water to obtain a solution with a mass fraction model HC1 at least 15%.

221,5 g raw BAD from the previous stage are placed in a three-neck reactor equipped with a thermometer, mechanical stirrer and reflux condenser, are added thereto 700 g of an aqueous solution of sodium carbonate, with a mass fraction PA3CO35.0% and stirred the mixture at 100-110oAnd atmospheric or pressure up to 0.7 MPa for 10 to 16 hours. Upon completion of the reaction the mixture is cooled and the separated organic phase containing the benzaldehyde. The obtained raw BAD distilled with steam, and then subjected to fractional distillation in wakemate to 1.0%. The output is BAD 94,9% of theoretical.

Example 2.

Synthesis is carried out similarly as described in example 1, based on 300 g of distilled bottoms production of benzyl chloride with mass fraction BH - 95,0%, HB - 3,0%, BTH to 0.8%, other impurities - 1.2% and 600 g of hydrochloric acid with a mass fraction of hydrogen chloride to 20.0%. Acid hydrolysis for 7 hours is carried out at 100-110oAnd atmospheric pressure, and then for a further one hour at 110-120oC and pressure up to 0.7 MPa. After division of the phases of the receive 204 g of crude benzaldehyde, which is subjected to alkaline hydrolysis at 100-103oAction 60 g of an aqueous solution of sodium carbonate, with a mass fraction of Na2CO3to 20.0% for 13 hours. Upon completion of the alkaline hydrolysis of raw BAD first distilled with steam, and then in vacuum. Get 183,3 g of benzaldehyde with mass fractions of the main substances that 98.9% of chlorine impurities to 0.9%. The output is BAD is 97.6%.

Example 3.

Synthesis is carried out according to the method of example 1, based on 300 g of bottoms the production of benzyl chloride with mass fraction BH - 84,5%, HB - 7,4%, BTH - 3,1%, other impurities of 5.0% and 600 g of hydrochloric acid with a mass fraction model HC1 - 26,0%. Kolotilina, which is subjected to alkaline hydrolysis at 100-105oWith step 210 g of an aqueous solution of sodium hydroxide with mass fractions of NaOH to 5.0%. Upon completion of the alkaline hydrolysis of raw BAD distilled with steam, and then in vacuum. Get 156,7 g of product with a mass fraction of benzaldehyde 99,0%, chlorinated impurities is 0.8%. The output is BAD 93,8%.

Example 4.

Synthesis is carried out according to the method of example 1, based on 300 g of a mixture of chlorinated aromatic compounds with a mass fraction BH - 95,0%, HB - 4,0%, BTH 0.4%, and other impurities - 0.6% and 270 g of hydrochloric acid with a mass fraction model HC1 - 15,0%. The duration of the acid hydrolysis of 10 hours. After cooling and division phases get 204,2 g raw BUD, who for 11 hours and stirred at 100-105oWith 45 g of sodium hydroxide solution with a mass fraction of NaOH 18,0%. The organic phase is separated, washed with water, taken in an amount of 20-100% by volume of the organic phase, and distilled in vacuum. Get 171,7 g of benzaldehyde containing 98,6 wt.% the basic substance and 1.1 wt.% organochlorine contaminants. Exit BAD 91,4%.

Other examples of the synthesis of benzaldehyde proposed method are presented in the table below. In all cases, the number of the original crude benzanthrone the Ah 8, 9, 13 and 14 raw BAD after alkaline hydrolysis was washed with water in an amount of 20-100% by volume of the organic phase and subjected to rectification. In other examples, the raw BAD first distilled with steam, and then the resulting benzaldehyde was subjected to fractional distillation in a vacuum. Formed in the first stage, hydrochloric acid, if necessary, diluted with water to obtain a solution with a mass fraction of HCl within the range of 15-26%. These solutions are then used in the following synthesis. As Quaternary ammonium salts (H) in examples 7, 11, 12, and 16 used triethylmethylammonium chloride, tributylammonium chloride, trimethylphenylammonium chloride, tetrabutylammonium chloride, or a mixture thereof. In examples 9 and 13 used glycols PEG-300, PEG-400, PEG-1000, or a mixture thereof. In all cases, it turns out benzaldehyde, satisfying the requirements of THE 2477-163-05763458-94.

From the presented examples, it follows that the proposed method allows to increase the output of benzaldehyde 6.1 to 12.5%, increase by 0.2-0.8% of the mass fraction of the main substances in the target product, and to use the process more affordable and cheap compared to the prototype of an alkaline agent such as carbonate or sodium hydroxide), and mixtures of chlorine aromatisantes benzaldehyde.

1. The method of producing benzaldehyde hydrolysis of benzylbromide or a mixture of chlorinated aromatic compounds with a mass fraction of benzylbromide within 75-95% in two stages: in the first stage, carry out the hydrolysis with an aqueous solution of hydrochloric acid at elevated temperature (acid hydrolysis), in the second stage, carry out the hydrolysis obtained in the first stage, raw benzaldehyde aqueous solution of alkaline agent (alkaline hydrolysis at elevated temperature, characterized in that the acid hydrolysis is carried out at a temperature of 100-120oWith at atmospheric or pressure up to 0.7 MPa, and alkaline hydrolysis is carried out at a temperature of 100-110oWith at atmospheric pressure or excess pressure up to 0.7 MPa using as the alkaline agent is an aqueous solution of sodium carbonate with a mass fraction of sodium carbonate in the range of 5-20% or aqueous sodium hydroxide solution with a mass fraction of NaOH in the range 5-18%.

2. The method according to p. 1, characterized in that in the first stage using hydrochloric acid solutions with a mass fraction of hydrogen chloride within the range of 15-26%.

3. The method according to any of paragraphs. 1-2, characterized in that the mass ratio of the original benzylbromide and solution of different topics the hydrolysis in the second stage is carried out in the presence of a phase transfer catalyst, taken in an amount of 0.02 to 0.5% by weight of the original benzylbromide.

5. The method according to p. 4, characterized in that as the phase transfer catalyst used Quaternary ammonium salts or surfactants nonionic type.

6. The method according to p. 5, characterized in that the Quaternary ammonium salts used triethylmethylammonium chloride, tributylammonium chloride, trimethylphenylammonium chloride, tetrabutylammonium bromide or mixtures thereof.

7. The method according to p. 5, characterized in that as surfactants, nonionic type use ethoxylated mono - and dialkylphenols, for example excipients OP 7, OP-10, or glycols, such as PEG-300, PEG-400, PEG-1000, or a mixture thereof.

8. The method according to PP. 1-7, characterized in that mixtures of chlorinated aromatic compounds with a mass fraction of benzylbromide within 75-95% use of untreated or subjected to a preliminary distillation distillation residues from the production of chloride benzyl.

9. The method according to any of paragraphs. 1-8, characterized in that the NYM steam, and then rectification.

10. The method according to any of paragraphs. 1-8, characterized in that the selection of benzaldehyde organic phase obtained in the second stage, washed with water, taken in an amount of 20-100% by volume of the organic phase, and then subjected to fractional distillation in a vacuum.

11. The method according to any of paragraphs. 1-10, characterized in that formed in the first stage hydrochloric acid diluted with water to obtain a solution with a mass fraction of hydrogen chloride within the range of 15-26% and use this solution at the stage of acid hydrolysis when performing the next operation.

 

Same patents:

The invention relates to organic chemistry, namely, the method of production of triptycene derivatives, in particular the production of Tris-formylrifamycin with substituents in positions of three different rings triptycene fragment

The invention relates to cyclic ketones, in particular, to an improved method for producing a square acid

FIELD: chemistry.

SUBSTANCE: terephthalic aldehyde is obtained from α,α,α',α'-tetrabromo-p-xylene while heating, followed by extraction of the end product. The method includes reacting α,α,α',α'-tetrabromo-p-xylene with O,O-dimethyl methylphosphonate at 180°C, and the end product is extracted from the reaction mass with isooctane.

EFFECT: method enables to obtain an end product with high output using a simple technique.

2 ex

FIELD: chemistry.

SUBSTANCE: invention refers to electrochemical method of primary and secondary alcohol oxidation to related carbonyl compounds including preparation of mother solution at room temperature. Then salt 2,2,6,6-tetramethylpiperidine hydrochloride of general formula is added to electrolyte solution consisting of oxidised alcohol, water, methylene chloride, sodium chloride and sodium sulphate with electrolysis on platinum electrodes at current strength 1.5 A and temperature 20-25°C.

EFFECT: higher technological effectiveness of process combined with reduced time for producing high-yield end product.

2 ex

FIELD: chemistry.

SUBSTANCE: method involves preparation of a reaction mixture at room temperature consisting of the alcohol to be oxidised, sodium bicarbonate, an organic solvent and a nitroxyl radical. Electrolysis is carried out on platinum electrodes with current of 1 A and temperature of 20-25°C. Potassium iodide is added to the reaction mixture. The organic solvent used is dichloromethane and the nitroxyl radical used is 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxyl of formula: with ratio of alcohol to nitroxyl radical equal to 10:1.

EFFECT: invention ensures high output of end products a within short period of time and less expenses on electricity using a high-technology method.

2 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing high-purity, halogen-free o-phthalaldehyde, having gas chromatography (GC) purity >99.5% of area, which can be used as an intermediate compound in production of paint, optical clarifying agent, in biocidal industry or photography. The disclosed method comprises the following steps: a) hydrolysis of tetrahalo-o-xylene at temperature 155-160°C and pressure 2-5 bars to o-phthalaldehyde which is b) converted in an acidic alcohol solution at temperature ranging from 0°C to boiling point with a reflux condenser to the corresponding dialkoxyphthalane and further, c) acetal is decomposed via acid hydrolysis at pH ranging from >1.5 to 7, thereby obtaining highly pure, halogen-free o-phthalaldehyde.

EFFECT: efficient method of producing high-purity, halogen-free o-phthalaldehyde.

5 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing 2,6-dimethyl-1-naphthaldehyde which is used in industrial chemical materials and raw materials for pharmaceutical products, pesticides, optical functional materials and electronic functional materials. The method involves formylation of 2,6-dimethylnaphthalene with carbon monoxide in the presence of hydrogen fluoride in terms of moles in amount ranging from 5- to 100-fold and boron trifluoride in terms of moles in amount ranging from 0.5- to 3.5-fold compared to the amount of 2,6-dimethylnaphthalene, and at reaction temperature ranging from 35 to 70°C.

EFFECT: method enables to obtain and end product with high selectivity.

15 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing 4-(4-alkylcyclohexyl)benzaldehyde or 4-(cyclohexyl)benzaldehyde, which can be used in chemical products used in materials for electronic equipment, including liquid crystals, and for pharmaceutical and agrochemical application. The invention also relates to versions of a method of producing 4-(trans-4-alkylcyclohexyl)benzaldehyde and a method of producing (trans-4-alkylcyclohexyl)benzene. The method of producing 4-(4-alkylcyclohexyl)benzaldehyde or 4-(cyclohexyl)benzaldehyde involves formylation of a benzene derivative of formula (1a) with carbon monoxide in the presence of hydrogen fluoride and boron trifluoride where R1 denotes an alkyl group containing 1-10 carbon atoms or a hydrogen atom. The hydrogen fluoride is used in amount of not less than 3 moles but not more than 20 moles, and boron trifluoride is used in amount of not less than 1.1 moles but not more than 5 moles per mole of the benzene derivative of formula (1a), and formylation is carried out at temperature from -50°C to 30°C.

EFFECT: invention enables selective synthesis of desired products with high purity.

10 cl, 15 ex

FIELD: chemistry.

SUBSTANCE: terephthalic aldehyde is obtained from α,α,α',α'-tetrabromo-p-xylene while heating, followed by extraction of the end product. The method includes reacting α,α,α',α'-tetrabromo-p-xylene with O,O-dimethyl methylphosphonate at 180°C, and the end product is extracted from the reaction mass with isooctane.

EFFECT: method enables to obtain an end product with high output using a simple technique.

2 ex

FIELD: chemistry.

SUBSTANCE: claimed invention relates to method for obtaining 4,4'-diformyldiphenylalkane, represented by means of the following formula (2), which is suitable as different industrial chemical initial substances and in production of initial substances for medications, agrochemicals, optic and electronic functional materials. Method includes formylation of diphenylalkane, represented by means of the following formula (1), with carbon monoxide in presence of fluorohydrogen and boron trifluoride, in which temperature of formylation reaction constitutes from -50 to 5°C, from 5 to 30 mol of fluorohydrogen are used per 1 mol of diphenylalkane and from 1.5 to 5 mol of boron trifluoride are used per 1 mol of diphenylalkane:

in which R represents alkanediyl group, containing from 1 to 6 carbon atoms, in which R represents alkanediyl group, containing from 1 to 6 carbon atoms.

EFFECT: claimed method makes it possible to obtain target products with high degree of purity and with high output.

6 cl, 1 tbl, 8 ex

FIELD: chemistry.

SUBSTANCE: method is to interact α,α,α',α'-tetrabrom-p-xylene with dimethyl acetal of benzaldehyde in the presence of the catalytic amount of zinc chloride at the temperature of 80°C, followed by isolation of the desired product by extraction from the reaction mixture with hot isooctane.

EFFECT: producing the desired product with high yield.

2 ex

FIELD: chemistry.

SUBSTANCE: method is to interact α,α,α',α'-tetrabrom-p-xylene with dimethyl acetal of benzaldehyde in the presence of a catalytic amount of zinc chloride at the temperature of 50°C, followed by isolation of the desired product by extraction from the reaction mixture with hot isooctane.

EFFECT: producing the desired product with high yield.

3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a novel aromatic aldehyde represented by the formula

having a branched alkyl group containing from 10 to 14 carbon atoms and to the method for its production, to an epoxy resin curing composition comprising a polyamine compound and the claimed aromatic aldehyde, to the compositions based on epoxy resin for coating, of civil engineering and construction, containing the claimed curing composition, to the cured coating film and to the cured material. In formula (II), each of the groups R1 and R2 independently represents an alkyl group having 1 to 12 carbon atoms, and the total number of carbon atoms in the groups R1 and R2 is from 9 to 13.

EFFECT: improving the properties of aldehyde.

9 cl, 12 dwg, 2 tbl, 15 ex

Up!